Semiconductor devices are used in a variety of electronic applications such as personal computers, cell phones, digital cameras, etc. To provide different functionalities for the different applications, integrated chips have circuits that use a wide range of active and passive devices. One commonly used passive device is an inductor. An inductor is a conductive coil having one or more turns, which is configured to store electrical energy in a magnetic field when electric current flows through it. Inductors are widely used in filters (e.g., RL filters), harmonic oscillators, and many other circuit components. The inductance L of an inductor may be calculated as:
      L    =                  μ        ⁢                                  ⁢                  N          2                ⁢        A            l        ,where L is inductance; μ is magnetic permeability; N is a number of turns of the inductor; A is area of the turns; and l is the length of the coil.